Ca^(2+)对生物膜形态结构及其组分的影响

Effect of Ca^(2+) on morphological structure and component of biofilm

通过向序批式生物膜反应器(SBBR)中投加Ca2+,考察Ca2+对生物膜形态结构及其组分的影响,探究Ca2+在生物膜形成中的作用影响规律及其对生物膜反应器运行的影响,以期能为含钙废水处理及优化废水处理效果提供理论指导。研究结果表明,Ca2+浓度增加有助于生物膜形成,并提高生物膜结构致密性;连续少量增加Ca2+(1~2 mg/L)有助于挂膜初期(约10 d)有机物去除;然而Ca2+浓度过高则会抑制生物膜活性,影响其降解性:当Ca2+浓度超过120 mg/L时,氨氮去除率出现下降,当Ca2+浓度超过280 mg/L时,有机物和总氮去除率显著下降。对生物膜及其胞外多聚物(EPS)组分的分析表明,Ca2+不会刺激微生物分泌产生更多EPS,但会导致生物膜干重增加。

The effects of Ca2 +on the morphological structure and component of biofilm were investigated by adding Ca2 +in the sequencing batch biofilm reactor( SBBR). The role of Ca2 +in biofilm formation and its impact on the operation of biofilm reactor were also analyzed to provide theoretical guidance for calcium-containing wastewater treatment and optimization of wastewater treatment. The results showed that the formation of microbial biofilm and the compactness of the biofilm structure were enhanced with the increase of the concentration of Ca2 +. Continuously increasing a small portion of Ca2 +( 1 to 2 mg /L) could facilitate the removal of organic compound during the initial period of biofilm formation( about 10d). However,the removal efficiency of ammonia nitrogen would be weakened as the concentration of Ca2 +exceeds 120 mg / L,and the removal of organic compound and total nitrogen would be reduced significantly when the concentration of Ca2 +exceeds 280 mg / L. This suggests that a higher concentration of Ca2 +would inhibit the activity and degradation of biofilm. Furthermore,Ca2 +could not promote the secretion of extracellular polymeric substance( EPS) while it could increase the dry weight of the biofilm from the component analysis of biofilm and EPS.